A total of 20 credit card providers have been referred to the Office of Fair Trading (OFT) by consumer group Which?
The body made the complaint after an investigation into the way credit card providers calculate interest rates.
Which? found that, between the 20 providers, there were 12 different systems of interest calculation in operation.
This places consumers at a disadvantage as it makes it difficult for them to make accurate comparisons between different credit cards, according to the group.
Alena Kozakova, principal economist for the group, said: “People believe that APRs are a dependable way of comparing credit cards, but our research shows that APR cannot to be relied upon for true comparisons.”
According to research conducted by Which?, 50 per cent of credit card holders think comparing APR allows them to effectively judge cards against each other.
The body referred the 20 card providers to the OFT under legal rights granted to consumer organisations that allow them to make “super-complaints” about big issues that affect a wide section of the population.
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